Conventional fiber optic cables comprise optical fibers that conduct light to transmit voice, video, and data information. An optical ribbon includes a group of optical fibers that are coated with a ribbon common layer, which may be of the ultraviolet (UV) light curable type. Typically, such a ribbon common layer is extruded about a group of individually colored optical fibers that have been arranged in a planar array, and is then irradiated with a UV light source that cures the ribbon common layer. The cured ribbon common layer protects the optical fibers and generally aligns the respective positions of optical fibers in the planar array. Optical fiber ribbons can be connected to multi-fiber connectors, for example, MTP connectors. MTP connectors can be used in LAN applications, for example, data centers and parallel optics interconnects between servers.
The present invention addresses the need for a fiber optic interconnection solution for multi-fiber connectors in the LAN environment. Conventional networking solutions, which utilize a 12-fiber MTP connector assembly, for example, are configured in a point-to-point system. Fiber polarity, i.e., based on a given fiber's transmit-to-receive function in the system, may be addressed by flipping fibers in one end of the assembly just before entering the multi-fiber connector in an epoxy plug, or by providing “A” and “B” type break-out modules where the fiber is flipped in the “B” module and straight in the “A” module.
System problems can occur when the MTP assembly is used in an interconnect construction. Fiber polarity is taken back out of the system when MTP assemblies are interconnected. FIG. 1 illustrates a conventional module “A” having six fiber pairs matched as follows: 1–2; 3–4; 5–6; 7–8; 9–10; and 11–12. All of the fiber pairs are defined by fibers that are immediately adjacent to one another in the optical fiber ribbon. The fiber pairs are routed to multi-fiber or single-fiber connectors 13 within module A, fiber 1 is immediately adjacent to fiber 2, fiber 3 next to fiber 4, and so on. Module A is used in a system utilizing an “A” and “B” type module approach where the fibers in the “B” module are flipped with respect to the fibers in module A to address, or correct for, fiber polarity.
In an effort to reduce implementation confusion, complexity and stocking issues with the “A” and “B” module method, or fiber flipping before entering the connector, another module available from the assignee of the present application is illustrated in FIG. 2. This module 60 is the subject of U.S. Pat. No. 6,758,600, the contents of which are incorporated by reference herein. In this module, a fiber sequence was devised that eliminated the need for an “A” and “B” module approach and replaced it with a universal wiring module. In the universal wiring module, the fibers from the optical fiber ribbon 20 are matched up (using the same numbering as in FIG. 1) 1–12; 2–11; 3–10; 4–9; 5–8; and 6–7 and illustrated in FIG. 2 as 21–32, 22–31, 23–30, 24–29 25–28, and 26–27 going to connectors 51–56 in breakout section 50. However, the MTP connector 40 in that universal module was mated key up to key up to another MTP connector, which suggests a flat polish on the end faces for the key up to key up orientation. As noted above, MTP connectors are typically connected in a key up to key down orientation, not in a key up to key up orientation. In an effort to adhere to the convention in MTP connectors of key up to key down mating, a new universal wiring module has been devised. Additionally, the reflectance performance of flat polished ferrules in the connectors is not sufficient for certain applications. Rather, a higher degree of optical performance (measured in dB drop) is required in certain systems.
Accordingly, the present invention is directed to a module that substantially obviates one or more of the potential problems and disadvantages in the prior art. Additional features and advantages of the inventions will be set forth in the description that follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the inventions will be realized and attained by the apparatus and process particularly pointed out in the written description and claims, as well as the appended drawings.